put one's finger on

It’s hard to put one’s finger on the cultural significance of Carlson’s conniption or Mars Wrigley’s retreat.

It’s hard to put one’s finger on it exactly.

One can’t quite put one’s finger on the changes: nothing radical or vulgar you understand, just aggressive tweaking: new carpeting, upholstery, lighting and fabrics.

But in a way that was a little hard to put one’s finger on, something felt a little off.

Posner is trying something different, it seems, with his latest Shakespeare production for the Folger, “The Winter’s Tale,” and what that constitutes is hard to put one’s finger on — and harder to like.